JP2008130103A - Audio player and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an audio player furnished with equalizer function capable of easily performing an optimum correction to a voice signal. <P>SOLUTION: A control section 109 of the audio player 100 controls a CD playback section 103 to play back audio data. The control section 109 controls a DSP 105 to detect a volume of the audio data with respect to a plurality of frequencies. The control section 109 compares the volumes of the audio data in the plurality of detected frequencies to discriminate the high/low of volumes. By the control section 109, the DSP 105 is controlled, and the volume of the audio data in the plurality of frequency bands is corrected to be optimum in accordance with the high/low of volumes of the audio data in the plurality of discriminated frequency bands. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an audio playback device having an equalizer function for correcting an audio signal.

  Currently, audio playback apparatuses having various equalizer functions for setting the playback sound to the user's favorite sound quality or the optimum sound quality when the user plays back music have been commercialized.

  For example, Patent Document 1 discloses an invention of an equalizer device that stores a plurality of frequency characteristic patterns and corrects an audio signal according to a frequency characteristic pattern selected by a user.

  Patent Document 2 discloses an invention of an equalizer device that determines a genre of music to be reproduced by a user, automatically sets a frequency characteristic pattern based on the genre, and corrects an audio signal according to the frequency characteristic pattern. Has been.

  Also known is an equalizer device in which a user manually adjusts a plurality of frequency levels, sets a frequency characteristic pattern, and corrects an audio signal according to the frequency characteristic pattern.

  However, with the equalizer device described in Patent Document 1, it is impossible to make fine settings. In addition, the equalizer device described in Patent Document 2 requires a large-scale database to discriminate genres, and is not suitable for a small-scale device. The equalizer device in which the user manually sets the frequency specifying parameter takes time and effort to adjust the levels of a plurality of frequencies.

Some recording media to be reproduced, for example, CDs (Compact Discs), are recorded with different recording characteristics. Also, the appropriate frequency characteristic pattern varies depending on the music genre. For this reason, even if an optimum frequency characteristic pattern is set for a certain recording medium, the set frequency characteristic pattern must be changed or reset when the recording medium is replaced. Such resetting work is a burden on the user.
Japanese Patent Laid-Open No. 11-150786 JP 2001-85962 A

The present invention has been made in view of the above problems, and an object of the present invention is to provide an audio reproducing apparatus having an equalizer function that can perform simple and appropriate correction.
It is another object of the present invention to provide an audio reproducing apparatus having an equalizer function capable of performing equalizing suitable for a recording medium and a music to be reproduced, and a program thereof.

In order to achieve the above object, an audio playback device according to the first aspect of the present invention provides:
An audio playback device having an equalizer function,
Volume determination means for analyzing audio data recorded on a recording medium to be reproduced and determining the volume indicated by the audio data for a plurality of frequencies;
Volume correction means for correcting the volume of the audio data in a plurality of frequency bands according to a correction characteristic based on a combination of volumes in a plurality of frequency bands determined by the volume determination means,
It is characterized by that.

For example, the audio data is composed of a plurality of music data,
The volume determination means determines a volume indicated by a predetermined number of pieces of music data among the plurality of pieces of music data for a plurality of frequencies,
The volume correction means determines a predetermined magnitude relationship of the volume of each frequency, and corrects the volume of the audio data in a plurality of frequency bands based on the determined magnitude relationship.
This may be a feature.

For example, the volume of the predetermined number of music data determined by the volume determination means is an average value or a maximum value of the volume indicated by the music data determined a predetermined number of times.
This may be a feature.

For example, the volume of the predetermined number of pieces of music data determined by the volume determination unit is an average value or a maximum value of the volume indicated by a predetermined part of the music data.
This may be a feature.

The program according to the second aspect of the present invention is:
Computer
Volume determination means for analyzing the audio data recorded on the recording medium to be reproduced and determining the volume indicated by the audio data for a plurality of frequencies;
Volume correction means for correcting the volume of the audio data in a plurality of frequency bands according to a correction characteristic based on a combination of volumes of the plurality of frequency bands determined by the volume determination means;
It is made to function as.

According to the present invention, it is possible to provide an audio playback apparatus having an equalizer function that can perform simple and appropriate correction.
In addition, it is possible to provide an audio reproducing apparatus having an equalizer function capable of performing equalizing suitable for a recording medium and a reproduction target music, and a program thereof.

  Hereinafter, an audio playback apparatus 100 according to an embodiment of the present invention will be described. The audio playback device 100 automatically performs sound quality correction according to the music data of the disc medium to be played back.

  As shown in FIG. 1, the audio playback apparatus 100 includes an operation unit 101, an MD (Mini Disc) playback unit 102, a CD (Compact Disc) playback unit 103, a selector 104, a DSP (Digital Signal Processor) 105, A D / A (Digital to Analog) converter 106, an amplifier 107, a speaker 108, a control unit 109, a tuner 110, a selector 111, an A / D (Analog to Digital) converter 112, and a bus 113. And. The audio playback device 100 can be connected to the external playback device 200 to acquire an analog audio signal.

  The operation unit 101 receives operation information from the user and supplies an operation signal corresponding to the operation to the control unit 109 via the bus 113. For example, when the control unit 109 receives an instruction from the user via the operation unit 101 to automatically set the equalizer, the control unit 109 controls the CD reproduction unit 103 and the DSP 105 to optimize the audio signal reproduced from the CD recording medium. The DSP 105 is set to correct the sound signal.

  The MD playback unit 102 includes an MD player, and plays back the music recorded on the MD recording medium based on the control of the control unit 109. Then, the reproduced digital audio signal is supplied to the DSP 105 through the selector 104.

  The CD playback unit 103 includes a CD player, and plays back music recorded on a CD recording medium based on the control of the control unit 109. Then, the reproduced digital audio signal is supplied to the DSP 105 through the selector 104.

The selector 104 includes, for example, a 2-input 1-output selection circuit and the like, and is controlled by the control unit 109.
The selector 104 inputs the audio signal supplied from the MD playback unit 102 and the audio signal supplied from the CD playback unit 103. Based on the control of the control unit 109, any one of the input audio signals is selected and supplied to the DSP 105.

The DSP 105 processes the digital audio signal supplied from the selector 104 or the A / D converter 112 based on the control of the control unit 109 and supplies the processed signal to the D / A converter 106.
Further, the DSP 105 measures the frequency characteristics of the digital audio signal supplied from the selector 104 or the A / D converter 112 and supplies the data about the measured frequency characteristics to the control unit 109.
As shown in FIG. 2, the DSP 105 includes an equalizer unit 1051, a volume adjustment unit 1052, and a spectrum analyzer unit 1053.

  For example, the equalizer unit 1051 includes a plurality of peaking filters. The equalizer unit 1051 performs processing on the digital audio signal supplied from the selector 104 or the A / D converter 112 so as to adjust the volume level in the seven bands (frequency bands) based on the control of the control unit 109. .

  Here, as shown in FIG. 3, the frequency band centered on 63 Hz is band 1, the frequency band centered on 160 Hz is band 2, the frequency band centered on 400 Hz is band 3, and 1 kHz is centered. A frequency band centered on 2.5 kHz is a band 5, a frequency band centered on 6.3 kHz is a band 6, a frequency band centered on 16 kHz is a band 6, and a band 6 A frequency band equal to or higher than the frequency band is designated as band 7. Here, the bands 1 to 3 are referred to as a low sound range, the band 4 is referred to as a medium sound range, and the bands 5 to 7 are referred to as a high sound range.

Under the control of the control unit 109, the equalizer unit 1051 can change the change amount (correction amount) of the volume level of each band in units of 1 dB between -8 dB and +8 dB. Here, the graph of the amount of change in each band and the corresponding volume level is called an equalizer curve.
The equalizer unit 1051 corrects and outputs the volume levels of the components of bands 1 to 7 of the supplied audio signal by a set change amount (−8 dB to +8 db), respectively. For example, when the control unit 109 is set in advance to bands 1, 2, 3, 4, 5, 6, and 7, +3 dB, -1 dB, +2 dB, +3 dB, -1 dB, -2 dB, and -3 dB are set. To do. In that case, the equalizer unit 1051 processes (edits) the supplied digital audio data for the band 1 so that the volume indicated by the audio data for the band 1 is increased by 3 db. The audio data is processed (edited) so that the volume indicated by the audio data is reduced by 1 db, and the audio data is processed (edited) based on the set amount of change for each of the bands 3 to 7 and output.

  The volume adjustment unit 1052 adjusts the volume level of the entire digital audio signal supplied from the equalizer unit 1051 based on the control of the control unit 109.

  The spectrum analyzer unit 1053 measures the frequency characteristics of the digital audio signal supplied from the equalizer unit 1051 and supplies data about the measured frequency characteristics to the control unit 109 via the bus 113.

  The D / A converter 106 converts the digital audio signal supplied from the DSP 105 into an analog audio signal and supplies the analog audio signal to the amplifier 107.

  The amplifier 107 amplifies the analog audio signal supplied from the D / A converter 106 and supplies it to the speaker 108.

  The speaker 108 outputs sound based on the analog sound signal supplied from the amplifier 107.

The control unit 109 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and controls the entire audio playback device 100. For example, the control unit 109 controls the overall reproduction operation of audio signals such as reproduction of music from CDs and MDs, reception reception reproduction of tuners, and input and reproduction of audio data from the external reproduction apparatus 200.
Furthermore, when the control unit 109 receives an instruction from the user via the operation unit 101 to automatically set sound quality correction when playing a CD recording medium, the control unit 109 controls the CD playback unit 103 and the DSP 105 to control the CD. Setting is performed so that the audio signal reproduced from the recording medium is corrected to an optimal audio signal. Hereinafter, this setting is referred to as equalizer automatic setting.

  The tuner 110 is composed of, for example, an AM / FM tuner or the like, receives a broadcast radio wave transmitted from a predetermined broadcast station under the control of the control unit 109, and supplies a demodulated analog audio signal to the selector 111.

The selector 111 includes, for example, a 2-input 1-output selection circuit and the like, and is controlled by the control unit 109.
The selector 111 receives the audio signal supplied from the tuner 110 and the audio signal supplied from the external playback device 200. Based on the control of the control unit 109, any one of the input audio signals is selected and supplied to the A / D converter 112.

  The A / D converter 112 converts the analog audio signal supplied from the selector 111 into a digital audio signal and supplies it to the DSP 105.

  The bus 113 is connected to the operation unit 101, the MD playback unit 102, the CD playback unit 103, the selector 104, the DSP 105, the control unit 109, the tuner 110, and the selector 111. Sends and receives data to and from the device.

  The external playback device 200 is, for example, a portable audio player or the like, and is connected to the audio playback device 100 and supplies a played back audio signal or a stored analog audio signal to the selector 111.

  Next, the operation of the audio playback apparatus 100 having the above configuration will be described with reference to FIGS.

The operation of reproducing audio data from various recording sources (recording medium (CD, MD), tuner, external reproduction device) executed by the audio reproduction device 100 is basically the same as a general reproduction operation.
That is, the control unit 101 controls the selectors 104 and 111 in accordance with a user instruction from the operation unit 109, and the audio data source is set to the MD playback unit 102, CD playback unit 103, tuner 110, and external playback device 200. Choose from either. The audio signal from the selected source is supplied to the DSP 105. The DSP 105 performs equalizing processing (band-specific volume correction processing) or the like on the supplied digital audio signal, converts it to an analog audio signal via the D / A converter 106, and emits sound from the speaker 108 via the amplifier 107. To do.

Next, an equalizer automatic setting process unique to this embodiment will be described.
First, referring to FIG. 4, an overall image of the equalizer automatic setting process will be described.
In the embodiment, the equalizer automatic setting process is performed only when the recording medium to be reproduced is a CD, and an equalizer curve is set according to the recording characteristics of the CD itself.

The user basically instructs the CD playback unit 103 to set the CD to be played back and to perform automatic equalizer setting via the operation unit 101.
When the user instructs to perform equalizer automatic setting via the operation unit 101, the control unit 109 determines whether or not the CD recording medium can be reproduced in the CD reproducing unit 103 (step S100).

  When the CD reproducing unit 103 determines that the CD recording medium is not reproducible (step S100; NO), the equalizer automatic setting process is terminated.

  When it is determined that the CD recording medium can be reproduced in the CD reproducing unit 103 (step S100; YES), the control unit 109 determines whether or not the CD recording medium is being reproduced in the CD reproducing unit 103 (step S200). ).

  If the CD playback unit 103 determines that the CD recording medium is not being played back (step S200; NO), the process proceeds to S400.

  If it is determined that the CD recording medium is being reproduced in the CD reproducing unit 103 (step S200; YES), the control unit 109 stops reproduction of the CD recording medium in the CD reproducing unit 103 (step S300).

  The control unit 109 controls the equalizer unit 1051 of the DSP 105 to set the amount of change in volume level in all bands to 0 dB (step S400).

  The control unit 109 performs a sampling process to be described later, and calculates the average sound volume at 100 Hz, 400 Hz, 2.5 kHz, and 10 kHz of five songs included in the CD recording medium (step S500).

  Based on the average sound volume calculated in the above sampling process, the control unit 109 performs an average sound volume comparison process, which will be described later, and calculates a plurality of parameters for determining an equalizer curve (step S600).

  The control unit 109 performs an equalizer curve determination process, which will be described later, based on the plurality of parameters calculated in the above average sound volume comparison process, and determines an equalizer curve (step S700).

  The control unit 109 sets the equalizer curve determined in the above equalizer curve determination process in the DSP 105, starts the CD playback unit 103 and controls the selector 104 so as to play the CD recording medium based on the equalizer curve. (Step S800).

  The above is the schematic operation of the equalizer automatic setting process.

  Next, sampling processing, average volume comparison processing, and equalizer curve determination processing performed in the equalizer automatic setting processing will be described in order.

  First, the sampling process performed in step S500 of the equalizer automatic setting process will be described. Briefly, in the sampling process, the audio playback device 100 has a predetermined number of songs included in the CD recording medium (here, 5 songs for ease of understanding) of 100 Hz, 400 Hz, 2. The average volume at 5 kHz and 10 kHz is calculated. These numerical values are determined in advance based on the difference in recording characteristics depending on the type of CD and the general frequency characteristics of music by genre of recorded music.

  Hereinafter, the sampling process (S500) will be described in detail with reference to FIG.

  First, the control unit 109 stores the value of the counter N indicating the number of music pieces as “1” (step S501).

  The control unit 109 stores the value of the counter M indicating the sampling number as “1” (step S502).

  The control unit 109 controls the CD playback unit 103 to search for a position of one minute from the beginning of the Nth song among the songs included in the CD recording medium (step S503).

  The control unit 109 controls the CD reproduction unit 103 to perform reproduction from a position one minute from the beginning of the Nth song included in the CD recording medium (step S504), and controls the spectrum analyzer unit 1053. Then, the sound volume at 100 Hz, 400 Hz, 2.5 kHz, and 10 kHz is measured (step S505).

  The control unit 109 determines whether or not the value of the counter M is “100” (step S506).

  If it is determined that the value of the counter M is not “100” (step S506; NO), “1” is added to the value of the counter M (step S509), and the process returns to step S505.

  If it is determined that the value of the counter M is “100” (step S506; YES), the average value of 100 times of the volume of the Nth song at 100 Hz, 400 Hz, 2.5 kHz, and 10 kHz is calculated and stored (step). S507).

  The control unit 109 determines whether or not the value of the counter N is “5” (step S508).

  If it is determined that the value of the counter N is not “5” (step S508; NO), the control unit 109 adds “1” to the value of the counter N (step S510), and returns the process to step S502.

  If it is determined that the value of the counter N is “5” (step S508; YES), the sampling process is terminated.

  Thus, according to the sampling process, the audio reproducing device 100 can detect the average sound volume at 100 Hz, 400 Hz, 2.5 kHz, and 10 kHz for five songs.

  Next, the average sound volume comparison process performed in step S600 of the equalizer automatic setting process will be described. Briefly, in the average sound volume comparison process, the audio playback device 100 compares the average sound volume calculated in the sampling process, and calculates a plurality of parameters for determining an equalizer curve.

  As shown in FIG. 6, among the songs whose average volume is calculated by the sampling process, the number of songs whose difference between the 10 kHz volume and the 2.5 kHz volume is equal to or greater than a threshold is calculated as a parameter A value, A song with a 2.5 kHz volume difference equal to or greater than a threshold is regarded as an old recording. The number of songs whose difference between the volume of 10 kHz and the volume of 2.5 kHz is less than the threshold is calculated as the value of parameter B.

  Similarly, the number of songs corresponding to the volume of 2.5 kHz, the volume of 400 Hz, and the volume of 400 Hz and 100 Hz is calculated as parameters C, D, E, F, G, and H.

  Hereinafter, the average volume comparison process performed by the control unit 109 will be described in detail with reference to FIG.

  First, the control unit 109 stores the values of parameters A, B, C, D, E, F, G, and H as “0”, and stores the value of the counter N as “1” (step S601).

  The control unit 109 compares the average volume of 10 kHz and 2.5 kHz of the Nth song calculated by the above sampling process (step S602).

  The control unit 109 determines whether or not the difference in the average volume between 10 kHz and 2.5 kHz of the Nth song is greater than or equal to a predetermined threshold value (step S603).

  If it is determined that the difference between the average volume of 10 kHz and 2.5 kHz of the N-th song is equal to or greater than a predetermined threshold (step S603; YES), “1” is added to the value of parameter A (step S604), and step S606. Proceed to

  If it is determined that the difference in average volume between the 10 kHz and 2.5 kHz of the N-th song is not equal to or greater than a predetermined threshold (step S603; NO), “1” is added to the value of parameter B (step S605), and step S606. Proceed to

  The control unit 109 compares the average volume of 2.5 kHz and 400 Hz of the Nth song calculated by the above sampling process (step S606).

  As a result of the comparison performed in step S606, the control unit 109 determines whether or not the average volume at 400 Hz is larger (step S607).

  If it is determined that the average volume at 400 Hz is larger (step S607; YES), “1” is added to the value of the parameter C (step S608), and the process proceeds to step S612.

  If it is determined that the average volume at 400 Hz is not higher (step S607; NO), the control unit 109 determines whether the average volume at 2.5 kHz is higher as a result of the comparison performed at step S606. (Step S609).

  If it is determined that the average volume of 2.5 kHz is not larger (step S609; NO), the control unit 109 adds “1” to the value of the parameter D (step S610), and proceeds to step S612.

  If it is determined that the average volume of 2.5 kHz is larger (step S609; YES), the control unit 109 adds “1” to the value of the parameter E (step S611), and proceeds to step S612.

  The control unit 109 compares the average volume of 400 Hz and 100 Hz of the Nth song calculated by the above sampling process (step S612).

  As a result of the comparison performed in step S612, the control unit 109 determines whether or not the average volume at 100 Hz is larger (step S613).

  If it is determined that the average volume at 100 Hz is larger (step S613; YES), “1” is added to the value of the parameter F, and the process proceeds to step S618.

  If it is determined that the average volume of 100 Hz is not larger (step S613; NO), the control unit 109 determines whether the average volume of 400 Hz is higher as a result of the comparison performed in step S613 (step S613). S615).

  If it is determined that the average volume at 400 Hz is not larger (step S615; NO), the control unit 109 adds “1” to the value of the parameter G (step S616), and proceeds to step S618.

  If it is determined that the average volume at 400 Hz is larger (step S615; YES), the control unit 109 adds “1” to the value of the parameter H (step S617), and proceeds to step S618.

  The control unit 109 determines whether or not the value of the counter N is “5” (step S618).

  If it is determined that the value of the counter N is not “5” (step S618; NO), the control unit 109 adds “1” to the value of the counter N (step S619), and returns the process to step S602.

  When it is determined that the value of the counter N is “5” (step S618; YES), the average sound volume comparison process is terminated.

  In this way, according to the average sound volume comparison process, the audio reproduction device 100 can calculate a parameter for determining an equalizer curve.

  Next, the equalizer curve determination process performed in step S700 of the equalizer automatic setting process will be described. Briefly, in the equalizer curve determination process, the control unit 109 determines an equalizer curve based on a plurality of parameters calculated in the average sound volume comparison process.

As shown in FIG. 8A, parameters A and B are compared, and if the value of parameter A is higher, the treble range is increased by 8 dB. If the value of parameter B is higher, the treble range is increased by 4 dB. The parameters C to E are compared. If the value of the parameter C is the highest, the midrange is increased by 8 dB. If the value of parameter D is the highest, no change is made in the mid range. If the value of parameter E is the highest, the midrange is lowered by 8 dB. The parameters F to H are compared, and if the value of the parameter F is the highest, the bass range is increased by 8 dB. If the value of parameter G is the highest, the bass range is increased by 4 dB. If the value of the parameter H is the highest, no change is made in the low sound range.
By these processes, parameters for specifying an equalizing curve corresponding to the recording characteristics of the reproduction target CD and the genre of the recorded music are set.

  As an example, it is assumed that the value of each parameter calculated by the audio reproduction device 100 in the average sound volume comparison process is as shown in FIG. When such parameters are set, according to the setting shown in FIG. 8A, the control unit 109 raises the high range by 8 dB, raises the mid range by 8 dB, and performs correction without changing the low range.

  The details of the equalizer curve determination process performed by the control unit 109 will be described below with reference to FIG.

  First, the control unit 109 determines whether or not the value of the parameter A calculated in the average sound volume comparison process is larger than the value of the parameter B (step S701).

  If it is determined that the value of the parameter A is larger than the value of the parameter B (step S701; YES), the control unit 109 increases the high frequency range (bands 5 to 7) of the equalizer curve by 8 dB (step S702). The process proceeds to S704. However, at the start of this process, the equalizer curve is 0 dB for all bands.

  If it is determined that the value of parameter A is not greater than the value of parameter B (step S701; NO), the control unit 109 increases the high frequency range (bands 5 to 7) of the equalizer curve by 4 dB (step S703). The process proceeds to step S704.

  The control unit 109 determines whether or not the value of the parameter C is the highest among the parameters C, D, and E calculated in the average sound volume comparison process (step S704).

  If it is determined that the value of the parameter C is the highest among the parameters C, D, and E (step S704; YES), the control unit 109 increases the midrange (band 4) of the equalizer curve by 8 dB (step S705), and the step The process proceeds to S708.

  If it is determined that the value of the parameter C is not the highest among the parameters C, D, and E (step S704; NO), the control unit 109 determines whether the value of the parameter E is the highest among the parameters C, D, and E. It is determined whether or not (step S706).

  If it is determined that the value of the parameter E is the highest among the parameters C, D, and E (step S706; YES), the control unit 109 lowers the midrange (band 4) of the equalizer curve by 8 dB (step S707). The process proceeds to S708.

  If it is determined that the value of the parameter E is not the highest among the parameters C, D, and E (step S706; NO), the process proceeds to step S708.

  The control unit 109 determines whether or not the parameter F has the highest value among the parameters F, G, and H calculated in the average volume comparison process (step S708).

  If it is determined that the value of the parameter F is the highest among the parameters F, G, and H (step S708; YES), the control unit 109 increases the low frequency range (bands 1 to 3) of the equalizer curve by 8 dB (step S709). Then, the equalizer curve determination process is terminated.

  If it is determined that the value of the parameter F is not the highest among the parameters F, G, and H (step S708; NO), the control unit 109 determines whether the value of the parameter G is the highest among the parameters F, G, and H. It is determined whether or not (step S710).

  If it is determined that the value of the parameter G is the highest among the parameters F, G, and H (step S710; YES), the control unit 109 increases the low frequency range (bands 1 to 3) of the equalizer curve by 4 dB (step S711). Then, the equalizer curve determination process is terminated.

  If it is determined that the value of the parameter G is not the highest among the parameters F, G, and H (step S710; NO), the equalizer curve determination process is terminated.

  In this way, according to the equalizer curve determination process, the audio playback device 100 can determine an equalizer curve for the CD recording medium to be played back.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation and application are possible.

  First, in the above embodiment, the equalizer curve is automatically set only when the recording medium to be reproduced is a CD, but it can also be set for a DVD or the like, and the source of audio data is arbitrary. is there.

  The sampling frequency is selected from 100 Hz, 400 Hz, 2.5 kHz, and 10 kHz for discriminating the CD type and the genre of the recorded music. The frequency to be sampled is set according to the type of music to be played (Gagaku, folk song, song, etc.).

  In addition, for each CD, an example is shown in which the sampling target is 5 songs and 100 samples per song, but the number of sampling target songs is arbitrary, and the sampling number per song is also arbitrary. However, if the total number of samplings is too large, it takes too much time to set, and if the number of songs or the number of samplings is too small, appropriate settings may not be performed, and it is necessary to balance.

  Moreover, in the said embodiment, although sampling started from the time of 1 minute from the start of a music, a start timing is arbitrary. However, it is desirable to set between 30 seconds and 1 minute in consideration of a so-called silent period. For example, if the music is very short, such as 1 minute 30 seconds or less, the time of 30 seconds is adjusted to be the sampling start time, and if longer than that, 1 minute is adjusted. May be. In addition, in the case of a music piece that is short enough to be sampled, the next music piece may be a sampling target.

  Similarly, the change amount of the volume level to be changed by each parameter or parameter may be changed.

  Moreover, in the said embodiment, it reproduced | reproduced several times per music, the average value of the sound volume in several frequencies was calculated | required, and the average value in several frequencies was compared. In an application example, the maximum volume may be sampled from among the volumes at a plurality of frequencies of the number of times played for one song, and the maximum volumes at a plurality of frequencies may be compared.

It is a block diagram which shows the structure of the audio reproduction apparatus which concerns on embodiment of this invention. It is a block diagram which shows the structure of DSP in FIG. It is a figure which shows the aspect of the variation | change_quantity of the volume level in each frequency band. It is a flowchart which shows an equalizer automatic setting process. It is a flowchart which shows a sampling process. 5 is a table for comparing each average sound volume obtained as a result of sampling processing and determining each parameter in the average sound volume comparison process. It is a flowchart which shows an average sound volume comparison process. (A) is the table | surface which showed what kind of correction | amendment was performed by each parameter obtained as a result of the average sound volume comparison process in an equalizer curve determination process, (b) is obtained as a result of the average sound volume comparison process. It is an example of a table of each parameter. It is a flowchart which shows an equalizer curve determination process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Audio reproduction apparatus 101 Operation part 102 MD (Mini Disc) reproduction part 103 CD (Compact Disc) reproduction part 104 Selector 105 DSP (Digital Signal Processor)
1051 Equalizer section 1052 Volume adjustment section 1053 Spectrum analyzer section 106 D / A (Digital to Analog) converter 107 Amplifier 108 Speaker 109 Control section 110 Tuner 111 Selector 112 A / D (Analog to Digital) converter 113 Bus 200 External playback device

Claims (5)

An audio playback device having an equalizer function,
Volume determination means for analyzing audio data recorded on a recording medium to be reproduced and determining the volume indicated by the audio data for a plurality of frequencies;
Volume correction means for correcting the volume of the audio data in a plurality of frequency bands according to a correction characteristic based on a combination of volumes in a plurality of frequency bands determined by the volume determination means,
An audio playback apparatus characterized by that. The audio data is composed of a plurality of music data,
The volume determination means determines a volume indicated by a predetermined number of pieces of music data among the plurality of pieces of music data for a plurality of frequencies,
The volume correction means determines a predetermined magnitude relationship of the volume of each frequency, and corrects the volume of the audio data in a plurality of frequency bands based on the determined magnitude relationship.
The audio reproducing apparatus according to claim 1, wherein The volume of the predetermined number of music data determined by the volume determination means is an average value or a maximum value of the volume indicated by the music data determined a predetermined number of times.
The audio reproducing apparatus according to claim 2, wherein The volume of the predetermined number of pieces of music data determined by the volume determination unit is an average value or a maximum value of the volume indicated by a predetermined portion of the music data.
The audio reproduction apparatus according to claim 3, wherein Computer
Volume determination means for analyzing the audio data recorded on the recording medium to be reproduced and determining the volume indicated by the audio data for a plurality of frequencies;
Volume correction means for correcting the volume of the audio data in a plurality of frequency bands according to a correction characteristic based on a combination of volumes of the plurality of frequency bands determined by the volume determination means;
A program characterized by functioning as

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